I have done one Deafblind interpreting assignment that involved eye surgery but have otherwise done a lot of medical interpreting, including interpreting for a deaf medical resident. Also, I used to be a pharmacy apprentice in the 70's working at two drug stores filling prescriptions and acquiring informal knowledge about drugs from that work.
The suggestion someone wrote that you can't advise where to put the IV I would disagree with. In doing in-services for nurses, I advise determining which hand is the non dominant hand and avoiding an arm board if possible for IVs. If there are medical reasons why these things can't be done, I doubt they will do it just because you say so and taking into account things that would maximize communication (such as having the dominant hand available for communication) is important and appropriate.
If it is general anesthesia, you don't have too much to worry about once the patient is ready to go to the operating room. Beforehand I would assume the consents, risks vs. benefits, what to expect would be conveyed as well as some of the questions mentioned below regarding intake of food and medicine prior to surgery.
Then it's just a matter of going to the "staging area" so to speak, which may require a change into scrubs or a "bunny suit". You should be dressed casually and not have valuables with you as there is not always a locker available. If you are a very undersized or oversized person, make sure they have your size ahead of time. (I'm a 3X male and there is usually only 2 sets of scrubs in the hospital that will fit me)
If it is twilight, the patient is "sort of" awake and sort of not. You might consider asking at some point, what medications will be used if you are or become familiar enough with them. Versed and Fentanyl (tranquilizer and short acting narcotic) are commonly used. Versed tends to make people forget a lot of what happens post Versed injection. It's not gonna matter that much at that point what you say as much as being generally supportive and instructive with regard to not moving, etc. In the deafblind that I did, I was in the operating room and basically held her hand through the procedure. She was mostly asleep and only woke briefly a few times.
If in the operating room, ask where you can sit and be aware that there is a "sterile field" that you must stay out of. It is the area immediately around the surgery site and make sure to ask what physical space you cannot cross.
Post op there is stimuli given to see how the patient is coming out of anesthesia. I suggest gently tapping on the guard rails of the bed as a replacement for the typical auditory stimulus given (or tactile in this case). This, in my experience, is more equivalent than touching the patient or trying to communicate something for determining arousability.
As the patient becomes more awake, you can then try actual communicating and the nurse will certainly ask about pain. They are using a 1 to 10 pain scale and you might be well advised to explain the pain scale in advance. Either that or use such terms as little bit, little bit-alot, medium, etc., to approximate the pain scale. 0 is no pain at all and 10 is the worst pain you ever had or could imagine.
Expect to repeat communications; both to and from the patient several times before it "sticks" at several minute intervals as guided by or following the nurse. I don't think it necessarily takes longer for a deaf patient to respond if the right kind of stimulus is used. The "howya doing, howya feeling" questions asked in the beginning I think is more for testing if the patient responds than if he or she understands or can answer. That's why I think a tap on the guard rails, at this particular juncture (the first thing done as they are watched in the recovery room at the time when waking is expected to begin), is the most appropriate and will produce the typical "eyes open" (then they close of course since the patient is not completely clear of the drugs yet) response. You can ask the nurse if they are looking for an actual answer or just the response
When the patient begins to wake enough and feel pain, IV pain medication will usually be offered. Certainly any allergy to any medications or past problems with surgeries/anesthesia will be asked about as will any orthopedic neck problems that could limit the backwards range of motion of the head (if the patient will be or if it becomes necessary to intubate for breathing during surgery - this is done after the patient is asleep and likewise extubated --the tube taken out-- before they wake) and whether anything comes out (dentures) or hearing aids.
Mostly some opiate is given but sometimes a non opiate like Toradol is given for post op pain. Drugs like Demerol, Morphine, Dilaudid, Numorphone are the usual narcotics and can produce, especially orthostaticly (upon standing or movement), nausea or vomiting. Know how to ask if the patient is feeling like vomiting from the pain medicine in which case they will be given one of 3 (there is a new one, I think) medications; Compazine, Tigan, or this new one. They give the pain medicine is small initial (and incremental) amounts to avoid side effects but the narcotics and perhaps Compazine can produce drowsiness again.
So, most of the work should be beforehand with the patient to work out these concepts and of course including what the patient should or should not do the day before surgery. Expect nothing by mouth after a certain time the day before to be explained and it will be asked the day of surgery (when was the last time you ate or drank anything) Also, if the patient is on any medications, she will be asked what the took already or should have been instructed at the doctor's office. If the patient is taking aspirin or any other drug that "thins" the blood, they should have been instructed what to do about that -- like discontinuing the aspirin 10 days before surgery, and they probably will be asked about that.